The possibility of oxygen enrichment of diesel and spark ignition engines has been the subject of research consideration, for example, in Ghojel J, Hilliard J. C. and Levendis J. A. "Effect of oxygen enrichment on the performance and emissions of IDI diesel engines." (SAE paper 830245, 1983), and Quader A. A. "Exhaust emissions and performance of a spark ignition engine using oxygen enriched air." (Combustion Science and Technology Vol. 19, pp 81-86, 1978). These researchers found that adding oxygen to enrich the fuel used resulted in decreased exhaust hydrocarbons emissions and higher exhaust nitric oxide emissions. More importantly, the results obtained indicated that fuel consumption was not improved and in fact was poorer leading to the conclusion that oxygen enrichment was not of any significant benefit.
It is the object of the present invention to provide certain improvements in oxygen enrichment procedures by means of which material improvements may be obtained.
Heavy fuel oils are traditionally not suitable for use in most high speed diesel engines, other than marine diesel engines. The difficulty is that such fuels ignite too slowly but when ignition occurs, it burns very rapidly and therefore can seriously damage the engine. For example, fuels such as residual or heavy fuel oils, alcohol and alcohol blends, seed oils and blends of light gas oil and heavy fuel oil or coal based fuels have not been able to be used for combustion in these engines.
It is therefore another object of the present invention to provide a method and system by means of which such fuels may be used in combustion engines.